Export thread

I have an issue with my Rato 670cc engine charging my battery. Its a new battery, but will not hold a charge. At full throttle, when I test the wire plug from the voltage regulator, it shows 13 to 14 volts. When I test the wire plug to the battery it shows 12.1 volts. When I connect the two plug wires together it still only reads 12.1 volts at the battery. Any suggestions as to why the voltage regulator is not sensing the battery voltage or something else I should be checking? Is it possible that the voltage regulator is still defective? Any advice is appreciated, Thanks.

I am thinking could be an issue where the system isn't grounding properly or there is an issue with the wire from the battery to the regulator plug. Basically will carry voltage but not carry amps.

With all the wires connected you can either connect a temporary wire from the +battery to the regulator output and see if it starts charging. That would rule out a bad regulator to battery wire, and can also take that wire from the -battery to the case of the regulator and see if it starts charging. If it charges then you have a ground problem. The same test can be done with the volt meter. meter should read 0 or close to it in both test.

I am assuming that the 13-14 volts is wire going to the battery and not 13-14 AC output from the charge stator.

ILENGINE said:

I am thinking could be an issue where the system isn't grounding properly or there is an issue with the wire from the battery to the regulator plug. Basically will carry voltage but not carry amps.

With all the wires connected you can either connect a temporary wire from the +battery to the regulator output and see if it starts charging. That would rule out a bad regulator to battery wire, and can also take that wire from the -battery to the case of the regulator and see if it starts charging. If it charges then you have a ground problem. The same test can be done with the volt meter. meter should read 0 or close to it in both test.

I am assuming that the 13-14 volts is wire going to the battery and not 13-14 AC output from the charge stator.

Click to expand...

Thanks Ilengine for the response. I'll try your recommendations. I've been reading some of your replies to folks having similar charging issues and you have provided me valuable information on testing the charging system. You mentioned in one of your replies about an ammeter in the circuit that could be causing the problem. I have and ammeter that lights up when I turn on the headlights, but it's not registering anything. Could this ammeter possibly be causing my problem, or could it not be registering due to the problem with the charging issue? I'll follow up and post my results after I run the tests you recommended. Thanks.

ILENGINE said:

I am thinking could be an issue where the system isn't grounding properly or there is an issue with the wire from the battery to the regulator plug. Basically will carry voltage but not carry amps.

With all the wires connected you can either connect a temporary wire from the +battery to the regulator output and see if it starts charging. That would rule out a bad regulator to battery wire, and can also take that wire from the -battery to the case of the regulator and see if it starts charging. If it charges then you have a ground problem. The same test can be done with the volt meter. meter should read 0 or close to it in both test.

I am assuming that the 13-14 volts is wire going to the battery and not 13-14 AC output from the charge stator.

Click to expand...

And yes, the 13-14 dc volts I am reading is from the B+ wire coming out of the voltage regulator. Thanks.

I reckon a wiring schematic might helpful....

ILENGINE said:

I am thinking could be an issue where the system isn't grounding properly or there is an issue with the wire from the battery to the regulator plug. Basically will carry voltage but not carry amps.

With all the wires connected you can either connect a temporary wire from the +battery to the regulator output and see if it starts charging. That would rule out a bad regulator to battery wire, and can also take that wire from the -battery to the case of the regulator and see if it starts charging. If it charges then you have a ground problem. The same test can be done with the volt meter. meter should read 0 or close to it in both test.

I am assuming that the 13-14 volts is wire going to the battery and not 13-14 AC output from the charge stator.

Click to expand...

And yes, the 13-14 volts I am reading is fron the B+ wire coming out of the voltage regulator.

StarTech said:

I reckon a wiring schematic might helpful....
View attachment 69731

Click to expand...

Thanks StarTech!

I ran a test wire from the B+ terminal of the voltage regulator to the positive post of the battery. On the multimeter, I was reading 13.5 volts. I assume the regulator is working to be getting that reading, when I was just getting 12.4 to 12.5 before. I want to suspect my problem is in the wiring from the regulator to the battery, except this happens when I power up additional loads to the system. On my led lights and panel lights, when on, the voltage reads at around 12.5 volts dc consistent. I have a 12 volt dc cooling fan for the hydraulics, that when switched on, it brings the voltage down to 11.8 volts dc. I run the fan consistently clear up to powering down the engine. I am wondering if that's where my problem could be, for when I shut down, the battery is at 11.8 volts. Your thoughts? Could this fan be the culprit drawing down that much power out of the battery, when I would think it would use the same amount of voltage as when the the lights are being used.
Any suggestions are appreciated, Thanks!

Got to ask. What engine speed it all this happening? Are you one of those that idle down and wonder why your battery is dead all the time? Please explain.

jmdls said:

I ran a test wire from the B+ terminal of the voltage regulator to the positive post of the battery. On the multimeter, I was reading 13.5 volts. I assume the regulator is working to be getting that reading, when I was just getting 12.4 to 12.5 before. I want to suspect my problem is in the wiring from the regulator to the battery, except this happens when I power up additional loads to the system. On my led lights and panel lights, when on, the voltage reads at around 12.5 volts dc consistent. I have a 12 volt dc cooling fan for the hydraulics, that when switched on, it brings the voltage down to 11.8 volts dc. I run the fan consistently clear up to powering down the engine. I am wondering if that's where my problem could be, for when I shut down, the battery is at 11.8 volts. Your thoughts? Could this fan be the culprit drawing down that much power out of the battery, when I would think it would use the same amount of voltage as when the the lights are being used.
Any suggestions are appreciated, Thanks!

Click to expand...

The question becomes what it the amp output of the charging system, and what is the watts/amp draw of running the lights and the cooling fan.

IL according to the wiring diagram for the Rato 670 the stator produces under 5 amps as it is fused at 5 amps. And battery is fused at 10 amps. So basically it is design mainly to recharge the battery and keep the fuel solenoid powered. Not much extra for anything else so it sounds like the OP is over taxing the system and the battery is having to provide the extra current that the alternator can't; otherwords, it cant keep up with the current draw and the battery starts draining. With the stator being fused at 5 amps I would say the stator is probably a 3 amp version.

I would be testing the amp draw to see if amp draw is too much. If it is then basically the only solution is either install a higher amp alternator, which I don't think is available for the Rato, or reduce the electrical loads.

StarTech said:

IL according to the wiring diagram for the Rato 670 the stator produces under 5 amps as it is fused at 5 amps. And battery is fused at 10 amps. So basically it is design mainly to recharge the battery and keep the fuel solenoid powered. Not much extra for anything else so it sounds like the OP is over taxing the system and the battery is having to provide the extra current that the alternator can't; otherwords, it cant keep up with the current draw and the battery starts draining. With the stator being fused at 5 amps I would say the stator is probably a 3 amp version.

I would be testing the amp draw to see if amp draw is too much. If it is then basically the only solution is either install a higher amp alternator, which I don't think is available for the Rato, or reduce the electrical loads.

Click to expand...

That would explain the battery drain and the issue the OP is having. I suspect that cooling fan if it is what I think it is has a 80 watt rating.

Hmmm if rated at 12V80W then that is pulling at least 6.67amps and it would be higher at around 7.5 amps @13.5V as resistance is the same just more voltage pushing amps.

This is one of things I don't like my household electrical system the service is at 135 vac so I am using more electricity than needed for 110-120 vac items and is wasted as heat. Otherwords my electric bill higher than it should be.

I have been thinking the same thing as well. However, all was working fine until just recently. I believe the cooling fan is what is affecting the load. When I run the the engine (full throttle) I have the 13.5 volts. When I turn on the cooling fan, voltage drops to about 11.8 volts. When I turn the fan switch off and turn on the headlights and dash panel lights, voltage returns to the 13.5 volts. I removed the cable from the positive battery terminal and engine continues to run, so it appears the voltage regulator is doing its job. When I run that cooling fan, it drops that battery voltage to 11.8 to 11.9 and keeps it there. When I shut down the engine, then not enough voltage to restart it appears. I'm thinking, I need to find another fan or one that doesn't have as much draw down on the system maybe. I have been looking around to see if I could find a stator replacement for more amps. This Rato engine looks identical in comparison to the HF Predator engine. Vegas Carts offers a stator and flywheel for the predator that can increase the amps with some modification. If this engine is identical to the Predator, I have read some threads where people are using Honda parts as a replacement as well. I would like for it to just work as it did before. Thanks all

I still wonder about that voltage regulator working correctly though, for when I turn on the cooling fan and the voltage drops to 11.8 volts and I shut it off, the voltage appears to remain around the 11.8 to 12 volt range, but when I turn on the lights, my voltage goes back up to the 13 to 13.5 volts range. Any thoughts on that? Thanks.